Cover for melting-pots



(No Model.)

J. A. ST. JOHN. COVER FOR MELTING POTS.

Patented Sept. 20, 1892.

UNITED STATES PATENT OFFICE.

JAMES A. ST. JOHN, OF ST. LOUIS, MISSOURI.

COVER FOR MELTlNG-POTS.

SPECIFICATION formingpart of Letters Patent No. 482,880, dated September 20, 1892.

Application filed October 14, 1891- Serial lie-408,653. (No model.)

To aZZ whom it may concern.-

Be it known that I, JAMES A. ST. JOHN, a subject of the Queen of England, residing in the city of St. Louis and State of Missouri, have invented certain new and useful Improvements in Covers for Melting-Pots, of which the following is a full, clear, and exact description.

My invention relates to means and devices for covering the material in melting-pots, and has for its object the provision of a device for such purposes that shall more effectuallyperform the functions required of such adevice. It consists in a cover adapted to float on the surface of the molten material.

The accompanying drawings,in which like letters of reference denote like parts in the several figures, are an illustration of an adaptation of my invention to the melting-pot of a type-casting machine.

Figure 1 is a perspective view of my cover and the top of a type-metal melting-pot. Fig. 2 is a diametrical cross-section of the same, taken as on the line 2 2 in Fig. 1.

The device as a whole consists, as shown, in a cover made to conform in outline to the contour of the interior of the pot or vessel in which it is to be used made imperforate, except atopenings necessary to accommodate such parts as are required to protrude through the cover and of a refractory material or combination of refractory materials of such a relative specific gravity as to adapt it to float on the molten material and act as a non-conductor of heat.

The cover, as illustrated in Fig. 2, consists in two sheets of sheet-iron A and B, secured together, preferably by turning over the edge a of the lower sheet A so as to overlap the edge of the upper sheet B, with a sheet of asbestus G interposed between them. The perforations D and E are formed in the cover to accommodate, respectively, the pump or plunger shaft and the rod operating the gate-valve. The cover as a whole is divided into two parts (see Fig. 1) G and H, secured together, preferably, by the hinges I, so that one (the smaller) part H can be turned up to the dotted-line position in Fig. 1, so as to permit ingots of new metal to be inserted into the pot P Without uncovering the whole surface of the molten metal.

The advantages in using my invention are these: Lying in close contact with the molten metal, it will prevent to a great degree the oxidation of the metal. It will economically facilitate the melting of the metal, the interposed layer of asbestus acting as a nonconductor, tending to retain the heat within the metal below it, causing a saving of fuel, which in practical tests has been found to be quite large. It will tend to a certain degree to prevent the loss of metal from volatilization. It will to a comparative degree prevent the escape of poisonous vapors from the melting- 0t. p As described, the cover constructed of sheet iron and asbestos is of a specific gravity lighterthan molten type-metal and will float on the surface of thesame.

The uses of my invention can obviously be extended and the cover can be constructed of such materials as to adapt it to be used in connection with and floated on molten varnish, glue, &c., and effect the same desirable advantages in that connection.

I claim' 1. A floating cover for molten metal, consisting of plates and an interposed filling of refractory material, substantially as and for the purposes described.

2. A sectional floating cover for molten metal, formed with openings for the passage of moving parts, said sections being hinged together, substantially as and for the purposes described.

3. The combination, with a melting-pot, of a floating cover therefor, consisting of plates and an interposed filling of refractory material, substantially as and for the purposes described.

In testimony whereof I have affixed my signature, in presence of two Witnesses, this 29th day of September, 1891.

. JAMES A. ST. JOHN.

Witnesses:

J os. W. CRooKEs, A. RAMEs. 

